Copolymerization products of compounds containing two or more cyanate groups with compounds containing two or more maleimide groups are known, for example, from U.S. Pat. Nos. 4,110,364; 4,287,014; 4,369,304: 4,370,467; 4,371,689; 4,373,086; 4,383,903; 4,393,195; 4,396,745: 4,404,330 and 4,469,859. Representative of said copolymerization products is the bismaleimide-triazine resin prepared by copolymerization of bisphenol A dicyanate and N,N'-(methylene-di-phenylene)bismaleimide. Preparation of said copolymerization products always requires premixing or contacting together two separate components: the polycyanate compound and the polymaleimide compound.
Hefner, Jr. in U.S. Pat. Nos. 4,680,378; 4,683,276; 4,731,426 and 4,769,440 provides novel compositions which simultaneously contain both a cyanate group and a maleimide group. Thus, said compositions avoid the premixing or contacting together of separate polycyanate and maleimide components to provide products containing cyanate group and maleimide group copolymerization structures.
The novel compositions of the present invention also simultaneously contain both a cyanate group and a maleimide group but additionally contain one or more mesogenic or rodlike moieties. The presence of one or more mesogenic or rodlike moieties serves to improve one or more physical or mechanical properties of the cured compositions relative to the cured compositions prepared using the cyanate functional maleimides of the prior art.